MIGRATION. 119 



LETTER XXXIV. 



TO THOMAS PENNANT, ESQ. 



SELBORNE, May 12, 1770. 

 DEAR SIR, 



LAST month, we had such a series of cold tur- 

 bulent weather, such a constant succession of frost, 

 and snow, and hail, and tempest, that the regular 

 migration, or appearance of the summer birds, was 

 much interrupted. Some did not show themselves 

 (at least were not heard,) till weeks after their usual 

 time ; as the black-cap and white-throat ; and some 

 have not been heard yet, as the grasshopper-lark and 

 largest willow- wren. As to the fly-catcher, I have 

 not seen it ; it is, indeed, one of the latest, but should 

 appear about this time ; and yet, amidst all this me- 

 teorous strife and war of the elements, two swallows 

 discovered themselves as long ago as the eleventh of 

 April, in frost and snow : but they withdrew quickly, 

 and were not visible again for many days. House- 

 martins, which are always more backward than swal- 

 lows, were not observed till May came in. 



Among the monogamous birds, several are to be 

 found, after pairing time, single and of each sex; but 

 whether this state of celibacy is matter of choice or 

 necessity, is not so easily discoverable. When the 

 house-sparrows deprive my martins of their nests, as 

 soon as I cause one to be shot, the other, be it cock 

 or hen, presently procures a mate, and so for several 

 times following. 



I have known a dove-house infested by a pair of 

 white owls, which made great havock among the 

 young pigeons : one of the owls was shot as soon as 

 possible ; but the survivor readily found a mate, and 



